Marlin and sailfish are the oceans’ perfect athletes. A marlin can outweigh a polar bear, leap through the air, and traverse the sea from Delaware to Madagascar. Sailfish can outrace nearly every fish in the sea. Marlin can hunt in waters a half mile down, and sailfish often head to deep waters too.

Yet in more and more places around the world, these predators are sticking near the surface, rarely using their formidable power to plunge into the depths to chase prey. The discovery of this behavioral quirk in fish built for diving offers some of the most tangible evidence of a disturbing trend: Warming temperatures are sucking oxygen out of waters even far out at sea, making enormous stretches of deep ocean hostile to marine life.

“Two hundred meters down, there is a freight train of low-oxygen water barreling toward the surface,” says William Gilly, a marine biologist with Stanford University’s Hopkins Marine Station, in Pacific Grove, California. Yet, “with all the ballyhoo about ocean issues, this one hasn’t gotten much attention.”

These are not coastal dead zones, like the one that sprawls across the Gulf of Mexico, but great swaths of deep water that can reach thousands of miles offshore. Already naturally low in oxygen, these regions keep growing, spreading horizontally and vertically. Included are vast portions of the eastern Pacific, almost all of the Bay of Bengal, and an area of the Atlantic off West Africa as broad as the United States. Globally, these low-oxygen areas have expanded by more than 1.7 million square miles (4.5 million square kilometers) in the past 50 years.

This phenomenon could transform the seas as much as global warming or ocean acidification will, rearranging where and what creatures eat and altering which species live or die. It already is starting to scramble ocean food chains and threatens to compound almost every other problem in the sea.

Scientists are debating how much oxygen loss is spurred by global warming, and how much is driven by natural cycles. But they agree that climate change will make the losses spread and perhaps even accelerate. “I don’t think people realize this is happening right now,” says Lisa Levin, an oxygen expert with the Scripps Institution of Oceanography, in San Diego.

Bad Water Rising.

Few understand marlin and sailfish better than biologist Eric Prince. He has studied them in Jamaica, Brazil, the Ivory Coast, and Ghana. He has examined their ear bones in Bermuda, taken tissue samples in Panama, and gathered their heads—with bayonet-like bills still attached—during fishing contests in Puerto Rico.

One day a decade ago, while tracking satellite tags attached to these fish, Prince saw something bizarre: Marlin off North Carolina fed in waters as deep as 2,600 feet (800 meters). But marlin off Guatemala and Costa Rica hovered high in the water, almost never descending beyond a few hundred feet. Sailfish followed a similar pattern. These billfish have special tissues in their heads that keep their brains warm in deep water. So why were they bunching up at the ocean’s surface? The culprit, it turned out, was a gigantic pool of low-oxygen water deep off Central America. These fish were staying up high, trying to avoid suffocating below.

Prince’s discovery came just as other scientists were figuring out that rising temperatures were expanding natural low-oxygen zones in the deep ocean, pushing them skyward by as much as a meter (three feet) per year.

Over the next decade, researchers figured out that this change already was driving marine creatures—sailfish, sharks, tuna, swordfish, and Pacific cod, as well as the smaller sardines, herring, shad, and mackerel they eat—into ever narrower bands of oxygen-rich water near the surface. “It leaves just a very thin lens on the top of the ocean where most organisms can live,” says Sarah Moffitt, of the Bodega Marine Laboratory at the University of California, Davis.

Congregating alongside their prey appears to be making some bigger fish fatter, as they burn less energy hunting. But living in such a compressed area also may be speeding the decline of top predators such as tuna, sailfish, and marlin by making them more accessible to fishing fleets.

“It makes the predators much more likely to be caught by the longline fleet,” says Prince, of the National Oceanic and Atmospheric Administration’s Southeast Fisheries Science Center in Florida. “Very slightly, every year, they become more and more susceptible to overfishing.” Oxygen is so central to life, even in the marine world, that its loss is harming animals in countless other ways, too.

Warming Waters Deplete Oxygen.

Fish, squid, octopus, and crab all draw dissolved oxygen from the water. And just as oxygen levels shift with elevation, oxygen at sea varies with depth. But in the ocean, oxygen is also dynamic, changing daily and seasonally with weather and tides or over years with cycles of warming and cooling.

Oxygen gets into the sea in two ways: through photosynthesis, which takes place only near the top where light penetrates, or through the mixing of air and water at the surface by wind and waves. Deep ocean waters hold far less oxygen than surface waters because they haven’t been in contact with air for centuries. And in many places, decomposing organic matter raining down from the surface uses up what little oxygen remains. These natural deep-water “oxygen minimum zones” cover great swaths of ocean interior.

They are far different from hypoxic coastal dead zones, which are multiplying, too, with more than 400 now reported worldwide. Dead zones are caused by nitrogen and other nutrients as rivers and storms flush pollution from farms and cities into nearshore waters.

The expansion of deep-sea low-oxygen zones, on the other hand, is driven by temperature. Warm water carries less dissolved oxygen. It’s also lighter than cold water. That leaves the ocean segregated in layers, restricting delivery of fresh oxygen to the deep and making these oxygen-poor zones much bigger.

Oxygen minimum zones (OMZs).

OMZs are not dead zones, but are vast mid-water areas far out at sea that hold less oxygen than surface waters do. Organic matter decomposes as it rains down from the surface, robbing OMZs of O2.

“The natural thing to expect is that as the ocean gets warmer, circulation will slow down and get more sluggish and the waters going into the deep ocean will hang around longer,” says Curtis Deutsch, a chemical oceanography professor at the University of Washington, in Seattle. “And indeed, oxygen seems to be declining.”

The zone off West Africa that’s as big as the continental United States has grown by 15 percent since 1960—and by 10 percent just since 1995. At 650 feet (200 meters) deep in the Pacific off southern California, oxygen has dropped 30 percent in some places in a quarter century.

Many scientists already suspect global warming is partly to blame for this transformation. Deutsch and others, however, think oxygen declines so far have been driven by complicated natural factors. Ocean conditions vary so much normally that they might be experiencing an unusual period of depletion—one that could moderate soon. But Deutsch called that “a very, very thin silver lining.”

Most researchers project that oxygen loss will keep driving many species toward the surface, reducing habitat for some and concentrating prey for birds, turtles, and other surface predators.

Winds in some regions will draw the oxygen-depleted water to the surface and push it onto shallower continental shelves. When oxygen drops there, some sensitive species that can’t move die. Even survivors experience stress, which can make them vulnerable to predators, disease, or overfishing.

This has already begun. The waters of the Pacific Northwest, starting in 2002, intermittently have gotten so low in oxygen that at times they’ve smothered sea cucumbers, sea stars, anemones, and Dungeness crabs. This biologically rich region—where winds draw waters from the deep 50 miles (80 kilometers) offshore and push them to the beach—is temporarily transformed into a lifeless wasteland.

“I look at it as a major reshaping of the ecosystem,” says Jack Barth, a chemical oceanographer at Oregon State University, in Corvallis.

Localized die-offs aren’t even the most disruptive effect of depleted oxygen. “Changes in oxygen turn out to be really important in determining where organisms are and what they do,” says marine biologist Francis Chan, also at Oregon State University. The fate of some odd little fish suggests the consequences can be enormous.

Into the Light.

Since the 1950s, researchers every year have dropped nets 1,000 feet (300 meters) down to catalogue marine life many miles off California. Most track commercially important species caught by the fishing industry. But J. Anthony Koslow tallies fish often credited with keeping marine systems functioning soundly—tiny mid-water bristlemouths, the region’s most abundant marine species, as well as viperfish, hatchetfish, razor-mouthed dragonfish, and even minnow-like lampfish. All are significant parts of the seafood buffet that supports life in the eastern Pacific, and all are declining dramatically with the vertical rise of low-oxygen water.

“If it was a 10 percent change, it wouldn’t have been worth noting, but they’ve declined by 63 percent,” says Koslow, of the Scripps Institution of Oceanography. And “what’s been amazing is it’s across the board—eight major groups of deep-sea fishes declining together—and it’s strongly correlated with declining oxygen.”

Most of these fish spend their days swimming hundreds of feet down, just above low-oxygen water. Many are black, camouflaged by the dark, deep waters where light never reaches. They rise at night to feed on plankton.

Koslow can’t say precisely why these fish populations have collapsed. But he suspects they, too, now spend more time closer to the surface seeking oxygen. That puts these fish during the day in a region where light penetrates, making them easier pickings for birds, marine mammals, rockfish, and other sight-feeders. If that’s the case, Koslow says, “the ramifications would be huge.”

Such tiny fish are a massive food source around the world. Globally, they account for far more mass in the sea than the entire world’s catch of fish combined. But there isn’t enough historical data in other parts of the world to determine if the trend is unique to California. “They are central to the ecology of the world’s oceans,” Koslow says.

Scientists suspect these fish already may be partly responsible for at least one surprising change—a massive northward expansion between 1997 and 2010 of the northern Pacific Ocean’s most ravenous visitor, the Humboldt squid. Once found from South America to Mexico, with occasional forays into California, the Humboldt squid has moved so far north that in recent years it has been seen off Alaska. Researchers tested squid in tanks and found low oxygen was hard on them, too, even though the jumbo squid could slow its metabolism. Yet here they were, faring so well at the edge of low-oxygen areas they had become a master predator of mid-water fish.

“These squid are out-competing all the tunas and sharks and marine mammals that may want to feed in this zone,” Stanford’s Gilly says. Researchers did not directly connect the expansion of the squid’s feeding area to rising oxygen-poor water. But Koslow linked low-oxygen water to shifts in where the mid-water fish on the squid’s menu live. And scientists now can draw a direct line between where those fish went and the squid’s northward march, Gilly says. “I think there might be a sweet spot for Humboldt squid, where low oxygen, food, and light are in perfect balance—and that’s accounting for their expansion,” Gilly says.

Still, the squid’s expansion was not subtle. Tracking its causes almost certainly is simpler than unspooling other impacts. And oxygen loss exacerbates other issues. Marine creatures need more oxygen in warmer waters, for example. Climate change means they increasingly will have less.

“I think we are changing the world; I just don’t think the responses are going to be as predictable as we think,” says Francisco Chavez, senior scientist with California’s Monterey Bay Aquarium Research Institute. “I think there are a slew of surprises ahead.” And how low-oxygen areas will affect everything else depends on how much they spread.

Looking Back to See Ahead.

To answer that question, scientists recently examined marine sediment cores from a period of glacial melt 17,000 to 11,000 years ago. During that time, global average air temperatures rose 3 to 4 degrees Celsius, the closest historical analog for the projected future, says study co-author Tessa Hill, of the Bodega Marine Laboratory. “The idea here is … let’s take an interval with somewhat analogous warming and see how low-oxygen zones responded,” Hill says.

The results: Low-oxygen areas exploded around the world. “What we found is that their expansion was just extremely large and abrupt,” says lead author Moffitt. “Their footprint across ocean basins grew much more than we had anticipated.”

One low-oxygen region off Chile and Peru—combined, the two countries now have an anchovy fleet that makes up the world’s largest single-species fishery—was much larger then, thousands of years ago. It stretched from 9,800 feet (3,000 meters) deep to within 490 feet (150 meters) of the surface. And off California, low-oxygen waters came far closer to the surface than they do today.

Their research showed that “environments we might think of as stable, like the deep ocean, may not be so stable at all,” Moffitt says. In the blink of an eye, geologically speaking, entire ocean basins changed. And many scientists suspect they are doing so once again, at a cost they can’t yet quantify.

The sale of a key government research unit to the outsourcing giant Capita could undermine essential work on food safety and lead to commercial concerns being put before the public interest, a leading expert has warned.

Professor Tim Lang, a Westminster adviser, told The Independent that the Food and Environment Research Agency (Fera), which led the way in identifying horsemeat in the UK food chain, is now doomed to failure. The global contractor has already outlined plans to almost double sales by making the unit’s work more commercial.

Fera’s research includes analysing diseases and chemical risks in the food-supply chain, as well as looking at the effects of pesticides, tree diseases and invasive species. But Professor Lang warns that once the agency is privatised, it will be under pressure to ignore low-paying projects vital to public safety and the environment in favour of more lucrative research. The academic frequently advises the Government and the World Health Organisation on food safety issues. “No one will pay for evidence about food and biodiversity, or food and pesticide residues,” he warned.

“There’s no profit in that. In fact, there’s more profit in not having it. There’s an absolute incentive not to have public-interest research about these areas. And that’s a concern.” He added: “Government needs to have optimum advice at its fingertips… Climate change, pesticides – all sorts of things that politicians ought to have good advice on are wrapped up in the daily bread and butter of Fera. And the Government privatising that basically gets rid of that.”

Capita formally takes over the agency next Wednesday. But Professor Lang, who heads City University London’s food policy unit, said: “I think it’s absolutely scandalous. This is selling the state, and the moment a state loses its access to science it’s in trouble.” He claimed many food policy experts shared his view but were unwilling to speak out about their concerns.

Fera employs about 400 scientists in York and a further 50 jobs will be created in the city as a result of the deal. The group made a profit of £1.6m last year as a government entity, on sales of about £40m. Capita wants to increase the unit’s annual sales to “at least” £700m over the next decade, or £70m a year.

Labour has urged caution over the deal. The shadow Environment Secretary, Maria Eagle, said the Government has not satisfied her concerns about Capita’s acquisition of the agency.

“I have some concerns about the deal and I have not been able to get much information out of the Government. Clearly the concern is that commercial considerations will skew Fera’s priorities,” she said.

The deal will result in Capita paying £20m for a 75 per cent stake in Fera; further investment will be made during the following five years. Capita is teaming up with Newcastle University for the venture, which it says will “unlock £14.5m of funding.”

Concerns have also been raised about a potential conflict of interest between Fera’s work and other Capita clients, which are thought to include the retailers Sainsbury’s and John Lewis.

“Growth will be generated through existing agreements with the public sector… and by further developing services to achieve greater penetration of the commercial market,” Capita said when it announced the deal. The group insisted yesterday that Fera, far from being damaged by the deal, would benefit once it separates from the Department for Environment, Food and Rural Affairs (Defra).

“Defra will continue to play a role in Fera’s operation and governance, and the government will continue to be an important client for Fera. More importantly, Capita believes that good science is good business… Capita’s investment will protect the excellent and valuable ‘science for public good’ work which is a distinctive part of Fera’s mission,” he said.

A spokesman for Fera said Defra would have two seats on the agency’s board so that it can ensure that the interests of the public and the government are represented. The Government has committed to contribute at least £50m to the unit over the next five years. “Scientific research will not be swayed by commercial interests,” he said. But despite assurances that the integrity of Fera will be protected, many in the industry remain concerned.

Professor Chris Elliott, the food expert who led the Government’s inquiry into the horsemeat scandal, said Fera scientists are relieved that the ownership issue has been settled after a long period of uncertainty, but he cautioned that considerable uncertainty remains.

“I doubt if they yet know the direction of travel planned for the organisation. I very much hope we can all get an idea of this sooner rather than later,” he said.

The Fera takeover comes as the National Audit Office investigates a contract between the Cabinet Office and Capita to provide civil service learning and development training, after a group of small businesses claimed the outsourcer had exploited its dominant position at the expense of the suppliers it works with. Capita said it was supporting the NAO contract review.

Explainer: What the agency does

The Food and Environment Research Agency’s (Fera) wide-ranging remit includes a crucial role in protecting the integrity of the UK’s food chain. It played a key role in the horsemeat scandal and celebrated its 100th anniversary last year – during which time it has established a global reputation for food science expertise.

But its remit is far wider than food. It also researches plants, animals and the environment at large, focusing on areas such as bee health, ash dieback, invasive species, genetically modified crops and biosecurity. It provides diagnostic and forensic support to, among others, the Plant Health and Seeds Inspectorate, the Genetic Modification Inspectorate and the National Bee Unit. Fera completes more than 600 research projects a year, involving the analysis of 50,000 plant and food samples.

New research at the University of Exeter and Bat Conservation Ireland has given the lie to the popular belief that streetlights are attractive to our common bat species because of the insect life they attract. The study found that in fact bat activity was lower in street-lit areas than in dark locations with similar habitat. And, in fact, the scientists have concluded bright lights are having a detrimental effect on bats.

Despite frequently being depicted as blind, bats have good eyesight that is adapted for low light conditions.

Dr Fiona Mathews from the University of Exeter says: “When we walk out of a lit house into the dark, it takes a while for our eyes to adapt to the darkness.

“The same is true in bats – they are dazzled by bright light and it takes time for their eyes to re-adjust. This could affect their ability to navigate.

“People rarely see bats, and when they do it is usually because they are silhouetted by a light.

“Because clouds of insects accumulate around lights, there has been an assumption that the bats were getting an easy lunch.

“However, it seems that their ability to hunt insects is reduced in the light. So although a bat may be seen flying round and round a streetlamp, it may actually be struggling to catch anything.”

The findings have important implications for conservation, overturning the previous assumption that common bats benefited from artificial lights for feeding.

The research, published in the journal Philosophical Transactions of the Royal Society B, found that the activity of soprano pipistrelle, noctule and serotine bats was similar or lower in areas with street lighting compared to dark areas. The only species for which lighting appeared favourable was Leisler’s bat, a species common in Ireland but rare in Britain.

An increase in the activity of our most common bat, the common pipistrelle, was only seen in locations where there was also a good amount of shelter from trees or hedgerows.

Dr Mathews says: “What our work shows is that they are actually usually just as active, if not more so, in adjacent dark areas.

“We already knew that lighting was bad news for rare species such as horseshoe bats. Now we have demonstrated that, for the common species which are of vital importance to our ecosystem, lighting is not helpful.

“Over recent decades, the number of streetlights, and the brightness of lighting, has grown enormously. We also use increasingly powerful lights to illuminate outdoor areas around our homes.

“We urgently need to reverse this trend.”

The research analysed large-scale surveys conducted in Britain and Ireland, involving more than 265,000 bat calls at over 600 locations.

The links between lighting and bats were explored at several spatial scales including car-surveys conducted by volunteers across Ireland, to shorter surveys conducted by bicycle, and detailed monitoring over multiple nights at specific sites.

Dr Niamh Roche of Bat Conservation Ireland commented: “Leisler’s bat is considered very special in Ireland since its population here is of international importance, so it is good to know that this species at least may not be so negatively impacted by street lighting.

“Nonetheless, we are extremely concerned that, with just one out of our nine Irish species showing a positive association with street lighting, much more needs to be done to lessen negative impacts of lighting.

“This can be achieved by considering lighting scheme designs more thoroughly from the planning stage.”

A rare continental butterfly which until last summer had only once before been seen in Britain has survived the winter, raising hopes it will breed here for the first time. The scarce tortoiseshell (Nymphalis xanthomelas) was spotted in unprecedented numbers in Kent, Lincolnshire, Suffolk and Norfolk last summer, after flying through Holland on a long migration from eastern Europe. One of the butterflies was seen again over two days last week in Holt country park, Norfolk, a sign it successfully hibernated over winter.

According to Butterfly Conservation’s head of monitoring, Dr Tom Brereton, the woods near Holt provide suitable conditions for the butterfly, which feeds on sap from birch trees in the spring and lays eggs on willows.

If fine spring weather helps females and males to find each other to mate, the butterfly, also known as the yellow-legged tortoiseshell because of its distinctive straw-coloured legs, will breed in Britain for the first time.

“This new sighting is a truly historic event as it marks the first time this stunning butterfly has ever overwintered successfully in Britain,” said Brereton.

“We’ve been waiting apprehensively over the last couple of weeks for news to see if any scarce tortoiseshells would emerge from hibernation following last year’s mini invasion. The butterfly prefers very cold winters and we weren’t sure if any would survive our mild season.

“If more emerge as we head into spring, 2015 could see the first UK-born scarce tortoiseshells on record.”

Until last summer, the only record of a scarce tortoiseshell in Britain was a single female seen near Sevenoaks in 1953. Usually found between China and eastern Europe, an unprecedented migration of this large, mobile butterfly last summer saw at least 30 sightings in Britain, mainly concentrated in Norfolk but also as far north as Tyneside and west to Devon.

The butterfly is very similar in appearance to the small tortoiseshells commonly found in gardens across Britain but the scarce tortoiseshell tends to be larger, with yellow legs and a yellow patch on its upper forewing instead of white.

An international team, led by researchers from the University of Oxford, UCL (University College London) and the Murdoch Childrens Research Institute in Australia, used DNA samples collected from more than 2,000 people to create the first fine-scale genetic map of any country in the world. Their findings, published in Nature, show that prior to the mass migrations of the 20th century there was a striking pattern of rich but subtle genetic variation across the UK, with distinct groups of genetically similar individuals clustered together geographically.

By comparing this information with DNA samples from over 6,000 Europeans, the team was also able to identify clear traces of the population movements into the UK over the past 10,000 years. Their work confirmed, and in many cases shed further light on, known historical migration patterns.

Key findings

There was not a single “Celtic” genetic group. In fact the Celtic parts of the UK (Scotland, Northern Ireland, Wales and Cornwall) are among the most different from each other genetically. For example, the Cornish are much more similar genetically to other English groups than they are to the Welsh or the Scots.

There are separate genetic groups in Cornwall and Devon, with a division almost exactly along the modern county boundary.

The majority of eastern, central and southern England is made up of a single, relatively homogeneous, genetic group with a significant DNA contribution from Anglo-Saxon migrations (10-40% of total ancestry). This settles a historical controversy in showing that the Anglo-Saxons intermarried with, rather than replaced, the existing populations.

The population in Orkney emerged as the most genetically distinct, with 25% of DNA coming from Norwegian ancestors. This shows clearly that the Norse Viking invasion (9th century) did not simply replace the indigenous Orkney population.

The Welsh appear more similar to the earliest settlers of Britain after the last ice age than do other people in the UK.

There is no obvious genetic signature of the Danish Vikings, who controlled large parts of England (“The Danelaw”) from the 9th century.

There is genetic evidence of the effect of the Landsker line — the boundary between English-speaking people in south-west Pembrokeshire (sometimes known as “Little England beyond Wales”) and the Welsh speakers in the rest of Wales, which persisted for almost a millennium.

The analyses suggest there was a substantial migration across the channel after the original post-ice-age settlers, but before Roman times. DNA from these migrants spread across England, Scotland, and Northern Ireland, but had little impact in Wales.

Many of the genetic clusters show similar locations to the tribal groupings and kingdoms around end of the 6th century, after the settlement of the Anglo-Saxons, suggesting these tribes and kingdoms may have maintained a regional identity for many centuries.

The Wellcome Trust-funded People of the British Isles study analysed the DNA of 2,039 people from rural areas of the UK, whose four grandparents were all born within 80km of each other. Because a quarter of our genome comes from each of our grandparents, the researchers were effectively sampling DNA from these ancestors, allowing a snapshot of UK genetics in the late 19th Century. They also analysed data from 6,209 individuals from 10 (modern) European countries.

To uncover the extremely subtle genetic differences among these individuals the researchers used cutting-edge statistical techniques, developed by four of the team members. They applied these methods, called fineSTRUCTURE and GLOBETROTTER, to analyse DNA differences at over 500,000 positions within the genome. They then separated the samples into genetically similar individuals, without knowing where in the UK the samples came from. By plotting each person onto a map of the British Isles, using the centre point of their grandparents’ birth places, they were able to see how this distribution correlated with their genetic groupings.

The researchers were then able to “zoom in” to examine the genetic patterns in the UK at levels of increasing resolution. At the broadest scale, the population in Orkney (islands to the north of Scotland) emerged as the most genetically distinct. At the next level, Wales forms a distinct genetic group, followed by a further division between north and south Wales. Then the north of England, Scotland, and Northern Ireland collectively separate from southern England, before Cornwall forms a separate cluster. Scotland and Northern Ireland then separate from northern England. The study eventually focused at the level where the UK was divided into 17 genetically distinct clusters of people.

Dr Michael Dunn, Head of Genetics & Molecular Sciences at the Wellcome Trust, said: “These researchers have been able to use modern genetic techniques to provide answers to the centuries’ old question — where we come from. Beyond the fascinating insights into our history, this information could prove very useful from a health perspective, as building a picture of population genetics at this scale may in future help us to design better genetic studies to investigate disease.”

Story Source: The above story is based on materials provided by Wellcome Trust. Note: Materials may be edited for content and length.

Thursday, March 12th. My daughter – a primary school teacher, had asked be if I would give a talk to her class on 18-19th century smuggling in Sussex, they currently doing a local history project on it. I duly put together a talk for her Year 4 pupils only to then be told that now the whole year was going to attend. Today, the appointed day arrived and it went off very well, they being attentive and asking a lot of questions afterwards. I sensed there was a warm, friendly atmosphere in the school; I also felt very proud of my daughter. School’s so very different from my day!

Friday, March 13th. Today we gathered in the four ponies on Lane End Common at Chailey, there being little left for them to eat and one pony was losing body condition. Commenced feeding the remaining 14 ponies on Red house Common; they will move to the un-fenced common when the road signs are in place. Later, we erected 800m of electric fencing on the National Trust’s Frog Firle property in readiness to move 11 ponies on to the steep Hindover Hill.

The Cuckmere valley still looks very wet – we being lucky for the water level had dropped sufficiently to drive along beneath Hindover to carry out the fencing. The problem I believe, is that the outfall flaps along the riverbank were when installed in the late 50’s, installed too low. They silt-up easily and require regular maintenance and now presumably with the EA’s cut-backs, they’re not being kept operational?

One such is an unexpected effect on green-house emissions. Researchers in Canada estimated how much the recovery of North American and Eurasian Beaver populations over the last 100 years has increased the amount of methane production, concluding that the higher numbers of Beavers now add about 800 million kilogrammes of methane annually to the atmosphere, about 15% of that from cud-chewing animals. This is a result of the recovery from hunting and reintroduction programmes, that has led to the creation of between 9,500 sq kms (and possibly as much as 42,000 sq kms) of ponded water and increased the ‘riparian interface’ by perhaps 200,000 km, both potent sources of methane. Researchers suggest these figures should be used with caution as the study makes quite a lot of assumptions.

Wild boars are returning to Istanbul as giant construction projects shrink their habitat in the city’s northern forests. Last week, a group of boars stormed the garden of a luxury housing complex in Sariyer on Istanbul’s European side, sending residents and a security guard running. The animals quickly disappeared into a nearby wood, but sightings of boars in the inner districts of Turkey’s largest city have become more frequent over the past months.

Ecologists and activists believe that Istanbul’s enormous construction projects are driving the boars from their natural habitat in the city’s northern forests, where a third Bosphorus bridge is nearing completion and a third airport is being built.

“We’re destroying their homes, their food sources,” said Onur Akgül of the Northern Forest Defence, a movement dedicated to protecting Istanbul’s remaining green spaces. “They can’t go north. They can’t go live in the sea. So they migrate into the city.”

When a boar was spotted swimming in the Bosphorus waters around the central Beyoğlu district in November, the forestry and water affairs minister Veysel Eroğlu dismissed the idea that construction was to blame, saying “the pig did what pigs do”.

Yet the locations of the third bridge and the new airport, planned to be the world’s largest, remain controversial and have provoked lawsuits and protests. “Instead of an ecosystem, we’ll have asphalt,” said Sedat Kalem, WWF Turkey’s conservation director.

“The ecological health of the area is lost. The incidents with the wild boars, that is one of the indicators of what is happening.” The northern forests and wetlands are considered to be vital for Istanbul’s sustainability, as the area produces much of the city’s drinking water. Twenty years ago, the then-mayor of Istanbul, Recep Tayyip Erdoğan, even described the prospect of a third bridge as “murder”.

Now, it seems hardly a day goes by without news of another mega-project. Last week, prime minister Davutoğlu announced a three-storey tunnel underneath the Bosphorus while president Erdoğan hoped to accelerate the construction of a canal that would turn Istanbul’s European side into an island.

“All of these big infrastructure projects are crossing those green areas in the north of the city, with the motorways, with the bridge, with the new airport and the planned canal,” said Kalem. He worries that the widespread deforestation accompanying these projects will do irreparable damage to Istanbul’s diverse ecosystem. The forests are an important bird migration corridor and host thousands of plant and animal species. With construction ongoing and millions of trees slated for removal, Kalem expects an increasing number of wild animals to escape into urban Istanbul.

“I think even more and more areas and species will be lost, unfortunately,” he added. “The size of excavation, of construction, is enormous. It’s something which we have not witnessed – ever.”

Tuba Inal Çekiç, of Istanbul’s chamber of urban planning, said that the construction would affect the city’s human population as much as its animals: deforestation would change the behaviour of winds and rain and increase already high pollution levels. The chamber therefore considers the northern forests a “red line.” You have to expand on the shore of the Marmara sea, not on the northern area, not on the Bosphorus,” Çekiç said. “Because that forest area is our lungs, the lungs of the city.”

How often do people visit the world’s protected areas (PAs)? Despite PAs covering one-eighth of the land and being a major focus of nature-based recreation and tourism, we don’t know. To address this, we compiled a globally-representative database of visits to PAs and built region-specific models predicting visit rates from PA size, local population size, remoteness, natural attractiveness, and national income. Applying these models to all but the very smallest of the world’s terrestrial PAs suggests that together they receive roughly 8 billion (8 x 109) visits/y—of which more than 80% are in Europe and North America. Linking our region-specific visit estimates to valuation studies indicates that these visits generate approximately US $600 billion/y in direct in-country expenditure and US $250 billion/y in consumer surplus. These figures dwarf current, typically inadequate spending on conserving PAs. Thus, even without considering the many other ecosystem services that PAs provide to people, our findings underscore calls for greatly increased investment in their conservation.